Numerous types of ventilator apparatus have been constructed for exhausting air from an attic region or the like. One type of ventilator apparatus is that which is part of a duct or shroud which forms an opening in a roof or gable to exhaust air therefrom. A fan or impeller is rotatable within the shroud to force movement of air therethrough. A cover member is attached to the shroud or to the building in spaced relationship from the shroud to protect the shroud and to provide a passage between the shroud and the cover member for flow of air therebetween. The existence of the fixed spaced-relationship between the shroud and the cover member is objectionable, due to the fact that insects, dirt, and other material can enter the upper portion of the building through the shroud when the apparatus is not in operation.
An object of this invention is to provide ventilator apparatus which is particularly adapted as air exhaust means for the upper region of a building, in which a closure member normally substantially closes an opening leading from the upper region of the building to the outside when the ventilator apparatus is not in operation, and in which the closure member is automatically moved to open position when the ventilator apparatus operates.
Another object of the invention is to provide such ventilator apparatus in which operation of the electric motor which rotates a fan or impeller of the ventilator apparatus also operates the closure member.
Other objects and advantages of this invention reside in the construction of parts, the combination thereof, the method of manufacture, and the mode of operation, as will become more apparent from the following description.